I use it on hearts or sunbonnet sue appliques. i do the Eleanor Burns of Quilt in a Day method where she traces the heart onto the fusible (non bumpy side) and places that on top of the fabric, sew on the traced line. then snip an opening in the fusible and turn right side out.
that turning places the bumpy side on the back and you fuse it to your background fabric and sew down by machine.